Officials in Colombia’s largest port city, Buenaventura, found four bodies in mass graves this week, raising concerns that rival drug trafficking organizations continue to disappear their victims in order to maintain a low homicide rate.

The remains, three of which are believed to belong to three young persons last seen earlier this year, were found in the neighborhood El Cristal. Officials discovered the bodies on the outskirts of the city and have stated they were victims of criminal gangs and ensuing rivalries.

“We drove to a stream known as San Antonio, in the rural zone of Buenaventura, where various bones were found,” stated the director of the CTI, the prosecution’s technical investigation unit, John Leibar Ibañez, to Blu Radio.

The official stated in the first search two bodies and a skull were discovered scattered under the rich soil, and in the second, a third body and various body parts, representing four victims in total.

A week ago the Minister of Defense, Luis Carlos Villegas, announced that the killings in Buenaventura had seen a reduction of 47% this year, claiming that in the approximate 300 days so far in 2015, there had been 255 days without violent deaths.

In fact, in October not a single victim was documented on the official record, according to Villegas.

With the discovery of the remains, which could belong to the three disappeared youth, various media have begun to question the accuracy of the minister’s data, insinuating that perhaps the homicide rates have been replaced by spikes in disappearances.

Buenaventura has historically been home to rampant, violent criminal gangs, being one of the most prized territories in Colombia’s underworld because of its strategic position for drug trafficking.

This violence in fueled by extreme poverty and political corruption: a large part of the city doesn’t have access to drinking water while its current mayor, like his two predecessors, is in jail.

The humanitarian crisis caused by the poverty and violence spurred the United Nations to call on Colombia’s national government to improve the city’s dire situation, but to no avail.